Histochemical Demonstration of Carbonic Anhydrase Activity in Some Epithelia Noted for Active Transport

Abstract

Abstract An improved histochemical method for demonstration of carbonic anhydrase has been applied to a number of epithelia engaged in electrolyte transport. Heavy staining was found close to or in the following regions: Intercellular spaces bordered with folded epithelial membranes (unpigmented epithelium of rabbit ciliary processes, straight segment of human eccrine sweat gland duct, rabbit gall‐bladder and villi of rat duodenum). Basal membrane infoldings (rat proximal and distal tubules, pigmented epithelium of rabbit ciliary processes). Intracellular canaliculi (parietal cells of rat stomach). Brush border of rat proximal tubule. Certain nuclei, but only in fixed sections and of dubious specificity. Moderate to weak staining was seen in several other places in the epithelial layers.